The Manipulating Subsystems. It seems impossible to avoid the anthropo- 
morphic terms, hands and arms, to refer to the manipulating devices. In 
general, however, these do not much resemble human hands or arms, but are 
designed specifically to perform tasks as required. It is extremely diffi- 
cult to rival the versatility of the human hand. However, special-purpose 
handlers can usually out-perform the human hand in either dexterity, 
strength, small size, or other specific attributes. In addition to having 
sufficient strength to handle the assigned tasks, Mobot manipulating sys- 
tems must be able to work in the presence of obstacles and to perform com- 
plex and intricate motions. 
The Senses. While all the human senses can rather readily be trans- 
mitted via electronic means, vision is the most important by far, and the 
only one which will be discussed in this brief analysis. 
Spatial orientation is normally accomplished by a variety of methods. 
Parallax, scale, relative motion, and the like, are probably most important 
of these. Binocular vision is surprisingly unimportant, as demonstrated by 
the fact that one-eyed men are but little handicapped in perceiving spatial 
orientations in their vicinity. Based on this analysis, excellent success 
has been obtained with a simple vision system utilizing two TV cameras, as 
shown in Figure 4. These two cameras show the operator two mutually per- 
pendicular projections of the area viewed, from which he can learn to deduce 
the spatial orientation of all objects within his visual field. Learning 
time of a few hours has proven quite adequate for this system. 
Certain special problems are often encountered in underwater viewing 
due to the fact that in many cases the ocean water is turbid or murky and 
presents a rather inadequate optical medium. A variety of methods are 
available to aid the operator's vision. For example, the skillful place- 
ment of artificial light sources may reduce the scattering of light by 
suspended particles in the water and improve operator visibility. The use 
of intense pulsed light sources synchronized with the frame-rate of the TV 
cameras may also be helpful. For long distance vision, sonar systems may 
be preferable to optical systems. While sonar systems are limited in their 
ability to resolve extremely fine details, they may furnish to the operator 
completely adequate information for navigation of his remote handling sys- 
tem until it comes within the rather limited range of the optical systems. 
As a general principle of Mobot system design, the engineer makes 
fullest use of all sensory inputs available to him. These may include, 
in addition to sonar and optical vision, touch, hydrostatic pressure, sys- 
tem attitude and heading, apparent speed and direction of water flow past 
the Mobot vehicle, and a variety of others. 
Locomotion. In order for the Mobot to move freely about in the under- 
water environment, several different means of locomotion are available. 
The remote handling engineer will select the one best suited to the parti- 
cular problem presented to him; in many cases a combination of Mobots em- 
ploying different means of mobility is the most economical solution. 
The distinction between handling and locomotion is an important one 
which is basic to effective handling system design. The term 'manipulation" 
is reserved for complex and delicate motions, as described in the section 
preceding. The term "locomotion" refers to the process of bringing the 
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